The Collaborative International Dictionary of English v.0.48:

Vague \Vague\, v. i. [F. vaguer, L. vagari, fr. vagus roaming.]
   To wander; to roam; to stray. [Obs.] "[The soul] doth vague
   and wander." --Holland.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Vague \Vague\, n.
   A wandering; a vagary. [Obs.] --Holinshed.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Vague \Vague\ (v[=a]g), a. [Compar. Vaguer (v[=a]g"[~e]r);
   superl. Vaguest.] [F. vague, or L. vagus. See Vague, v.
   i.]
   [1913 Webster]
   1. Wandering; vagrant; vagabond. [Archaic] "To set upon the
      vague villains." --Hayward.
      [1913 Webster]

            She danced along with vague, regardless eyes.
                                                  --Keats.
      [1913 Webster]

   2. Unsettled; unfixed; undetermined; indefinite; ambiguous;
      as, a vague idea; a vague proposition.
      [1913 Webster]

            This faith is neither a mere fantasy of future
            glory, nor a vague ebullition of feeling. --I.
                                                  Taylor.
      [1913 Webster]

            The poet turned away, and gave himself up to a sort
            of vague revery, which he called thought.
                                                  --Hawthorne.
      [1913 Webster]

   3. Proceeding from no known authority; unauthenticated;
      uncertain; flying; as, a vague report.
      [1913 Webster]

            Some legend strange and vague.        --Longfellow.
      [1913 Webster]

   Vague year. See Sothiac year, under Sothiac.
      [1913 Webster]

   Syn: Unsettled; indefinite; unfixed; ill-defined; ambiguous;
        hazy; loose; lax; uncertain.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Vague \Vague\, n. [Cf. F. vague.]
   An indefinite expanse. [R.]
   [1913 Webster]

         The gray vague of unsympathizing sea.    --Lowell.
   [1913 Webster]

WordNet (r) 3.0 (2006):

vague
    adj 1: not clearly understood or expressed; "an obscure turn of
           phrase"; "an impulse to go off and fight certain obscure
           battles of his own spirit"-Anatole Broyard; "their
           descriptions of human behavior become vague, dull, and
           unclear"- P.A.Sorokin; "vague...forms of speech...have so
           long passed for mysteries of science"- John Locke [syn:
           obscure, vague]
    2: not precisely limited, determined, or distinguished; "an
       undefined term"; "undefined authority"; "some undefined sense
       of excitement"; "vague feelings of sadness"; "a vague
       uneasiness" [syn: undefined, vague] [ant: defined]
    3: lacking clarity or distinctness; "a dim figure in the
       distance"; "only a faint recollection"; "shadowy figures in
       the gloom"; "saw a vague outline of a building through the
       fog"; "a few wispy memories of childhood" [syn: dim,
       faint, shadowy, vague, wispy]

Moby Thesaurus II by Grady Ward, 1.0:

223 Moby Thesaurus words for "vague":
   abstract, aimless, airy, aleatoric, aleatory, ambiguous, amorphic,
   amorphous, amphibological, anarchic, attenuate, attenuated, baggy,
   bland, blank, blear, bleared, bleary, blind, blobby, blurred,
   blurry, boyish, broad, capricious, casual, chance, chancy, chaotic,
   characterless, clear as mud, clouded, cloudy, collective,
   concealed, confused, dark, delicate, desultory, diaphanous,
   diluted, dim, disarticulated, discontinuous, disjunct, disordered,
   disorderly, dispersed, disproportionate, doubtful, dreamlike,
   dreamy, dull, empty, equivocal, erratic, ethereal, expressionless,
   faint, featureless, feeble, filmy, fine, fine-drawn, finespun,
   fitful, flimsy, foggy, formless, frail, frivolous, fuzzy, gauzy,
   general, generalized, generic, girlish, gossamer, gracile,
   gratuitous, half-seen, half-visible, haphazard, hazy, hidden,
   hit-or-miss, ill-defined, immethodical, imprecise, in doubt,
   inaccurate, inchoate, incoherent, inconspicuous, inconstant,
   indecisive, indefinable, indefinite, indeterminable, indeterminate,
   indiscriminate, indistinct, indistinguishable, inexact, inexplicit,
   inform, insubstantial, irregular, irresolute, kaleidoscopic, lacy,
   lax, light, loose, low-profile, lumpen, meaningless,
   merely glimpsed, misshapen, misty, murky, mushy, nebulous, neutral,
   nondescript, nonspecific, nonsymmetrical, nonsystematic,
   nonuniform, obscure, opaque, orderless, out of focus, pale, papery,
   planless, promiscuous, puzzled, random, rare, rarefied,
   semivisible, senseless, shadowed forth, shadowy, shapeless,
   shrouded, slender, slenderish, slight, slight-made, slim, slimmish,
   slinky, small, spasmodic, sporadic, stochastic, straggling,
   straggly, subconscious, subliminal, subtle, svelte, sweeping,
   sylphlike, systemless, tenebrous, tenuous, thin, thin-bodied,
   thin-set, thin-spun, thinnish, threadlike, transcendent,
   unarranged, uncertain, uncharacterized, unclassified, unclear,
   undecided, undefined, undestined, undetermined, undifferentiated,
   undirected, unexplained, unfixed, ungraded, unintelligible,
   unjoined, unmethodical, unordered, unorganized, unplain,
   unrecognizable, unsettled, unsorted, unspecific, unspecified,
   unsubstantial, unsymmetrical, unsystematic, ununiform, vacant,
   vacillating, vacuous, vaporous, vapory, veiled, wandering,
   wasp-waisted, watered, watered-down, watery, wavering, weak, wide,
   willowy, wiredrawn, wishy-washy, wispy